Ventilating Device with Alternating Airflows

ABSTRACT

The application relates to a ventilation device adapted to alternately direct a first and a second airflow to a first and a second heat-absorbing body in order to achieve a heat transfer between the two airflows. The device comprises a first and a second integral connection element adapted to allow communication with the first and the second heat-absorbing body, and a third and a fourth integral connection element adapted to allow conduction of the first and the second airflow to and/or from the device. The device further comprises an airflow control arrangement connected with the integral connection elements via control arrangement openings and adapted to alternately direct the airflows to the respective integral connection elements

This application is a continuation of application Ser. No. 12/994,778filed Nov. 26, 2010 which is a 371 of PCT/SE10/50069 filed Jan. 26,2010.

The present invention relates to a ventilation device adapted to controla first and a second airflow to alternately pass to or from a first anda second heat-absorbing body in order to achieve a heat transfer betweenthe two airflows.

Heating and cooling the interior of buildings consumes large amounts ofenergy, generating costs both in terms of monetary and environmentallosses. One source of energy loss is building ventilation where indoorair at a desired temperature is exchanged for outdoor air having anone-desired temperature, so that the introduced air must continuouslybe either heated or cooled. One method for decreasing the energyconsumption comprises exchanging heat energy between the incoming andoutgoing air. One such method comprises alternately letting the incomingand outgoing air heat and cool two heat energy absorbing bodies. Forexample, if the temperature of the outdoor air is cooler than thedesired indoor air temperature, in a first state the cold, incoming airis heated by a first body, which has previously been heated by outgoingair, while the warm, outgoing air heats a second body, and in a secondstate, the incoming air is directed to pass through and be heated by thesecond body, while the outgoing air re-heats the first body.

One device commonly used for directing an incoming and an outgoingairflow to alternately pass through two heat-absorbing bodies comprisesa box-like housing provided with four openings arranged one on each ofthe four sides of the housing, and one or more shutter plates arrangedto rotate inside the housing for alternately directing the airflowsbetween one of two openings to the heat-absorbing bodies. The devicechanges the path of an airflow by deflecting the airflow substantiallyperpendicularly relative to its previous flow direction. One drawbackwith this construction is that since the openings must necessarily belocated one on each side of the housing due to the construction of theshutter plates, the air ducts leading to the device will extend indifferent directions, so that it becomes difficult and expensive toinstall the device in a ventilation system, especially in a pre-existingventilation system.

In U.S. Pat. No. 7,059,385 another example of a ventilation device foralternating two airflows is shown. The device comprises twoheat-absorbing bodies arranged in parallel and provided with rectangularopenings for allowing an airflow therethrough. The openings areconnected with two air ducts, such that each air duct covers half ofboth openings. The device further comprises rotating deflectors arrangedbetween the bodies and the air ducts, and provided with two openingswhich each have an area of about one quarter of the deflector's surfacearea. By rotating the deflectors 90 degrees the two deflector openingsare moved to allow airflow from only one of the air ducts to each body,and hence the airflows may be alternated through the bodies. Onedrawback with this device is that the airflow will mostly beconcentrated to the half of the body which is open to the deflectoropening. Thus the efficiency of the device will be decreased, especiallysince the deflector openings will allow communication with a differenthalf of the body for each respective air flow. Furthermore, since theairflows are intended to be alternated about once every minutethroughout the lifetime of the device, wear on the moving components ofthe ventilation device is quite severe, and it is both difficult andexpensive to make a disc-like deflector resistant to fatigue.

Another problem within this field is that for large buildings hugevolumes of air must be moved, requiring air ducts with largecross-sections. A ventilation device for alternating the flow paths musttherefore also be large with large and heavy shutters or deflectors,increasing both wear and the energy consumption for turning the shuttersor deflectors. In particular, it is difficult to manufacture a largedeflector of the type in U.S. Pat. No. 7,059,385 for large volumes ofair.

SUMMARY OF THE INVENTION

One object of the present invention is to indicate a ventilation devicewhere an airflow control device causes alternating two airflow pathsbetween two heat-absorbing bodies, which device is simple to install ina ventilation system of a building including ducts to communicatebetween the interior and exterior of the building.

According to the present invention there is provided a ventilationapparatus for connection between an exterior and an interior of abuilding so that:

in a cooling operation, when air in the exterior is hotter than air inthe interior, heat is extracted from an exterior air flow passing fromthe exterior to the interior to cool the exterior air flow passing tothe interior; and

in a heating operation, when the exterior air is cooler than theinterior air, heat is extracted from an interior air flow passing to theexterior from the interior to heat the exterior air flow passing to theinterior;

the apparatus comprising:

a first heat absorbing body and a second heat absorbing body;

a first airflow passageway for connection to the interior of thebuilding so that an airflow can pass therethrough to introduce exteriorair into the building;

a second airflow passageway for connection to the interior of thebuilding so that an airflow can pass therethrough to extract interiorair from the building;

a third airflow passageway for connection to the exterior of thebuilding so that an airflow can pass therethrough to pull exterior airinto the building;

a fourth airflow passageway for connection to the exterior of thebuilding so that an airflow can pass therethrough to expel interior airout of the building;

a first air control module having a first end and a second opposed end;

and a second air control module having a first end and a second opposedend;

the first heat absorbing body having first and second air passage facesat opposite ends thereof and four closed sides between said ends;

the second heat absorbing body having first and second air passage facesat opposite ends thereof and four closed sides between said ends;

the first heat absorbing body being arranged so as to:

-   -   a) transfer hot thermal energy to the first heat absorbing body        from air passing through the first heat absorbing body when a        temperature of the air is higher than the first heat absorbing        body so as to store hot thermal energy in the first heat        absorbing body; and    -   b) transfer cold thermal energy to the first heat absorbing body        from air passing through the first heat absorbing body when a        temperature of the air is lower than the first heat absorbing        body so as to store cold thermal energy in the first heat        absorbing body;

the second heat absorbing body being arranged so as to:

-   -   a) transfer hot thermal energy to the second heat absorbing body        from air passing through the second heat absorbing body when a        temperature of the air is higher than the second heat absorbing        body so as to store hot thermal energy in the second heat        absorbing body; and    -   b) transfer cold thermal energy to the second heat absorbing        body from air passing through the second heat absorbing body        when a temperature of the air is lower than the second heat        absorbing body so as to store cold thermal energy in the second        heat absorbing body;

the first and second heat absorbing bodies each mounted with one of saidfour closed sides of the first heat absorbing body lying adjacent to andparallel to one of said four closed sides of the second heat absorbingbody and with the first air passage face of the first heat absorbingbody lying alongside the first air passage face of the second heatabsorbing body and with the second air passage face of the first heatabsorbing body lying alongside the second air passage face of the secondheat absorbing body;

the first and second airflow passageways being located at a first end ofthe first air control module and the first face of the first heatabsorbing body and the first face of the second heat absorbing bodybeing located at a second opposed end of the first air control module;

the third and fourth airflow passageways being located at a first end ofthe second air control module and the second face of the first heatabsorbing body and the second face of the second heat absorbing bodybeing located at a second opposed end of the second air control module;

the first and second air control modules being arranged to switch theair flows between the first and second heat absorbing bodies at bothends of the heat-absorbing bodies so that:

in a first mode of the cooling operation the interior air flow isswitched by the first air control module to pass from the second airflowpassageway through the first heat absorbing body and is switched by thesecond air control module to pass to the fourth airflow passageway tothe exterior to store cold thermal energy in the first heat absorbingbody while the exterior air flow does not pass through the first heatabsorbing body but instead is passes through the third airflowpassageway and is switched by the second air control module to passthrough the second heat absorbing body and is switched by the first aircontrol module to pass to the interior through the first airflowpassageway;

and in a second mode of the cooling operation the interior air flow isswitched by the first air control module to pass from the second airflowpassageway through the second heat absorbing body and is switched by thesecond air control module to pass to the fourth airflow passageway tothe exterior to store cold thermal energy in the second heat absorbingbody while the exterior air flow does not pass through the second heatabsorbing body but instead passes through the third airflow passagewayand is switched by the second air control module to pass through thefirst heat absorbing body and is switched by the first air controlmodule to pass to the interior through the first airflow passagewaywhile being cooled by the cold thermal energy stored in the first heatabsorbing body which has been cooled in the first mode;

in a first mode of the heating operation the interior air flow isswitched by the first air control module to pass from the second airflowpassageway through the first heat absorbing body and is switched by thesecond air control module to pass to the fourth airflow passageway tothe exterior to store hot thermal energy in the first heat absorbingbody while the exterior air flow does not pass through the first heatabsorbing body but instead passes through the third airflow passagewayand is switched by the second air control module to pass through thesecond heat absorbing body and is switched by the first air controlmodule to pass to the interior through the first airflow passageway;

and in a second mode of the heating operation the interior air flow isswitched by the first air control module to pass from the second airflowpassageway through the second heat absorbing body and is switched by thesecond air control module to pass to the fourth airflow passageway tothe exterior to store hot thermal energy in the second heat absorbingbody while the exterior air flow does not pass through the second heatabsorbing body but instead passes through the third airflow passagewayand is switched by the second air control module to pass through thefirst heat absorbing body and is switched by the first air controlmodule to pass to the interior through the first airflow passagewaywhile being heated by the hot thermal energy stored in first heatabsorbing body which has been heated in the first mode.

Preferably the first and second airflow passageways are rectangular withfour sides with one side of the first airflow passageway lying paralleland adjacent to one side of the second airflow passageway and whereinthe third and fourth airflow passageways are rectangular with four sideswith one side of the third airflow passageway lying parallel andadjacent to one side of the fourth airflow passageway.

Preferably the first and second airflow passageways face in a commondirection at the first end of the first air control module, and thethird and fourth airflow passageways face in a common direction awayfrom the first and second airflow passageways at, the first end of thesecond air control module.

Preferably the first and second heat absorbing bodies are stacked one ontop of the other.

Preferably the first air passage faces lie in a common plane and thesecond air passage faces lie in a common plane.

Preferably the first, second, third and fourth passageways, the firstand second air control modules and the first and second heat absorbingbodies are formed as a common assembly for common installation in thebuilding for attachment to interior and exterior ducts within thebuilding.

Thus it is possible to pass the first airflow from the first airflowchannel, connected with the first body, and into the second airflowchannel, connected with the second body, wherein the path of the firstairflow is changed from passing through the first body to passingthrough the second body. Hence, rather than having to lead the airflowto a separate, box-like house provided with shutter plates for changingthe path of the airflow to different openings in the house, or having toprovide an expensive deflector in an interface between two air ducts andtwo heat-absorbing bodies, the invention comprises passing the airflowdirectly from the first airflow channel and into the second airflowchannel.

Hence, the device may be designed to be very compact and small inrelation to its flow capacity. Furthermore, since the airflow is passedfrom one channel and further into the other channel the size of thedevice may be nearly in the same range as two air ducts with the sameflow capacity. According to one embodiment, the openings of the airflowchannels leading to the heat-absorbing bodies are designed to fit thesize of the heat-absorbing bodies, so that each opening overlaps for atleast a major part, and preferably covers at least 90%-110%, and mostpreferably at least 97-103%, of the area of the opening to the body.Hence, the efficiency of the heat-exchange increases.

Furthermore, the device is simple to install into a pre-existing or aplanned ventilation system. This is due to that the device can easily beadapted and fitted to the dimensions and/or shape of the ventilationsystem, since the channels may be provided at any position and may beoriented in any direction in relation to the external ventilationsystem. In particular, there is neither need for a separate housing withair ducts extending in all directions, nor of a deflector arranged in acomplicated interface.

Another advantage is that the device according to the invention may bedesigned to have a large airflow capacity since both the air channelsleading to the bodies and the air passage between the air channels mayeasily be designed having large cross-sections. Hence, the device isvery efficient and is also both more simple and less costly to installand to manufacture.

A heat-absorbing body is preferably made with a material and shapeadapted to efficiently transfer heat to, and absorb heat from, anairflow passing through the body. Preferably the body is designed tohave a large surface area to allow the rapid transfer of heat energy toand from the airflow. According to one embodiment the body comprises aplurality of thin metal plates stacked together and arranged to form amultitude of air channels between the plates for conducting theairflows.

An airflow channel is considered to comprise any form of air duct, pipe,hose, or chamber intended to be connected with a heat-absorbing bodywith one end, either directly or indirectly via additional connectionelements, and to be connected with an external ventilation system withthe other end of the airflow channel. The external ventilation systempreferably comprises either an intake or outlet for the airflow to theindoor or outdoor air, and correspondingly the airflow may be eitherincoming or outgoing air. The airflow channel is also preferablydesigned to form a single, continuous unit. The air passage between thefirst and the second airflow channels may correspondingly comprise anair duct, pipe or the like.

According to one embodiment the airflow channels are arranged to followeach other's shapes. Preferably the airflow channels are furtherarranged with similar size and shape. Preferably the airflow channelsare also arranged to be parallel. According to one embodiment theairflow channels are substantially straight and arranged to havesubstantially similar cross-sectional shape and area. Preferably thecross-sectional shape of the airflow channels is rectangular. Preferablythe airflow channels are also arranged close to each other. Morepreferably the airflow channels are connected with each other along thelength of the channels, so as to form one common unit. Preferably, theairflow channels are arranged to form two parallel airflow channelsinside one common body of the ventilation device.

Throughout this application, for ease of description only and withoutinvoking any limitations on the scope of protection, the first airflowchannel is assigned to receive and/or exhaust the first airflow to orfrom a ventilation system via a first end of the first channel, whilereceiving and/or exhausting either the first or the second airflow at asecond end, adapted to be connected with a first heat-absorbing body.Correspondingly, the second airflow channel is assigned to receiveand/or exhaust the second airflow to or from the ventilation system viaa first end of the second channel, while receiving and/or exhaustingeither the first or the second airflow at a second end, adapted to beconnected with the second heat-absorbing body. It should be appreciatedthat the naming and numbering of the airflows, air channels, airpassages, heat-absorbing bodies etc. is made only for descriptivepurposes and is in all other respects arbitrary. Similarly, the airflowsmay flow through the air channels and bodies in both directions,depending on the manner in which the device is arranged in theventilation system. Also, either of the first or second airflows couldbe incoming or outgoing air. According to one embodiment the air passagecomprises at most three passages arranged to collectively lead at leasta major part, preferably at least 60%, and more preferably at least 90%,of the airflow through the air passage. Hence, the air passage isarranged to hold the airflow together in at most three large streams.According to one embodiment the air passage comprises one major passagearranged to lead at least a major part of the airflow in one singleflow. Hence, the air passage is arranged to hold the airflow together inone large stream, so that at least half of the total airflow is kepttogether into one and the same stream. Preferably the air passage isarranged to hold the airflow together so that more than 60%, preferablymore than 90%, and most preferably at least 95% of the airflow is kepttogether into the same, single stream. Preferably the air passagecomprises only one single air passage, wherein the entire airflow iskept together in the same stream, apart from possible leakage.Preferably the cross-sectional area of an opening into the air passageis at least between 30-60% of the cross-sectional area of the airflowchannel. Preferably the cross-sectional area of one single opening intothe air passage is at least between 30-60% of the cross-sectional areaof the airflow channel. Hence the pressure drop is considerablydecreased. The measure of flow is here considered to follow thedefinition of mass/time.

According to one embodiment of the invention the ventilation devicecomprises at least one airflow control member adapted to control theflow of at least one airflow through the ventilation device, so that thealternation of the airflows to the heat-absorbing bodies may becontrolled. An airflow control member may comprise a shutter plate, adamper, a deflector or a gas throttle valve, arranged to control, shutoff or change the flow or the flow path of an airflow, depending on itspresent state. Preferably, at least one airflow control member ispositioned inside the first or the second airflow channel. The innervolume of the airflow channels is large to allow large airflows. Bypositioning the airflow control member inside one of the channels, thelarge space in the channels is utilized, so that the device as a wholemay be more compactly designed. According to one embodiment of theinvention the ventilation device comprises a first airflow controlmember adapted to admit the first airflow to flow into the secondchannel through the first air passage in a first, open state and toforce the first airflow to continue through the first airflow channel ina second, closed state. Preferably, the first airflow control member isalso adapted to prevent at least a major part, preferably at least 90%,and most preferably at least 98%, of the second airflow from enteringthe first air passage and the second airflow channel in its second,closed state. Thus the entering of the first airflow into the secondairflow channel may be controlled. Also it may be ensured that at leasta major part of the first airflow continues through the first airchannel without leaking into the air passage in the second state of thefirst airflow control member. Thus mixing of the two airflows isdecreased or may even be completely avoided.

According to another embodiment of the invention the ventilation devicecomprises a second airflow control member adapted to admit the firstairflow to flow past the air passage and to continue through the firstairflow channel in a first, open state, and to force the first airflowinto the first air passage in a second, closed state, so as to preventat least a major part of the first airflow from flowing through thefirst airflow channel in a second, closed state. Thus it may be ensuredthat at least a major part of the first airflow passes into the airpassage and further into the second channel in the second state of thesecond airflow control member. Preferably, the second airflow controlmember is adapted to force at least 90%, preferably at least 98%, of thefirst airflow into the first air passage in its second state.

According to another embodiment of the invention the ventilation devicecomprises a control module adapted to control the first and the secondairflow control members to alternate between being in the first and thesecond states, respectively, wherein the control module is furtheradapted to control the first and the second airflow control members tobe in different states at the same time. Thus, when the first controlmember is in the open state admitting the first airflow into the airpassage, the control module controls the second control member to be inthe closed state so as to force the first airflow into the first airpassage, and vice versa. Hence it is ensured that at least a major part,preferably at least 90%, and most preferably at least 98%, of the firstairflow is led into the second airflow channel when the first airflowcontrol member is in the first state, and continues in the first channelwhen the first airflow control member is in the second state. Thecontrol module may comprise a mechanical construction, a controlcircuitry and/or a computer with a computer program, or any suitablecombinations thereof. The control module may also be divided intoseveral pieces of equipment or may be integrated into only one piece.

According to one embodiment of the invention the ventilation devicecomprises a second air passage between the first and the second airflowchannels arranged for leading at least a part of a second airflow fromthe second airflow channel and into the first airflow channel. Hence thepath of the second airflow may also be changed to either continue in thesecond channel and further to the second body, or to be passed into thefirst channel and further to the first body. Preferably, the ventilationdevice also comprises a third airflow control member adapted to admitthe second airflow to flow into the second air passage and further tothe first airflow channel, in a first, open state, and to force thesecond airflow to continue through the second airflow channel in asecond, closed state. Thus the third airflow control member prevents atleast a major part, preferably at least 90%, and most preferably atleast 98%, of the second airflow from flowing into the second airpassage and further to the first airflow channel, in the second, closedstate. Preferably, the first and second airflow control members areshaped to each cover at least between 30-60% of the internal,cross-sectional area of the respective airflow channels in their closedstates.

According to one embodiment the two airflow passages are preferablyarranged side-by-side. Preferably the air passages are also parallel toeach other. Preferably the device comprises a wall separating the firstand second air passages from each other, so that the airflows flow oneon either side of the wall. Thus the wall separates the two airflowsfrom each other. Preferably, the air passage or air passages arearranged to hold each, respective airflow together into at least onelarge, airflow, so that at least half of each, respective airflow iskept together into one and the same stream, respectively. Preferably theair passage or air passages are arranged to hold each, respectiveairflow together so that more than 60%, preferably more than 90%, andmost preferably at least 95% of each, respective airflow is kepttogether into the same, single airflow. By keeping each of the airflowstogether rather than letting the airflow be divided into a plurality ofsmaller flows, there is less heat transfer between the airflows when theairflows passes through the air passages. Hence, there is lessdifference in heat transfer between the airflows depending on whetherthe airflows are directed through the air passage or straight throughthe air channels. Preferably, the air passage comprises two or less,more preferably only one, separating wall separating the two airflows toflow on either side. Thus there is provided a small surface area betweenthe two airflows in order to achieve a low heat transfer.

According to one embodiment of the invention the ventilation devicecomprises a fourth airflow control member adapted to admit the secondairflow to flow past the second air passage and to continue through thesecond airflow channel in a first, open state, and to force the secondairflow into the second air passage in a second, closed state, so as toprevent at least a major part of the second airflow from flowing throughthe second airflow channel. Thus at least a major part of the secondairflow is forced to pass into the first airflow channel and further tothe first heat-absorbing body in the second state of the fourth controlmember. Preferably the fourth airflow control member is adapted to forcea major part, preferably at least 90%, of the second airflow into thefirst channel in the closed state, and most preferably at least 98%.Preferably the device also comprises a control module adapted to controlthe third and the fourth airflow control members to alternate betweenbeing in the first and the second states, respectively, wherein thecontrol module is further adapted to control the third and the fourthairflow control members to be in different states at the same time. Theairflow control members are hence arranged to redirect the airflows toalternately pass straight through the ventilation device through thefirst and second airflow channels respectively, and to be interchanged,so that the airflows passes into the other of the airflow channels viathe air passages.

According to one embodiment of the invention the ventilation devicecomprises a control member adapted to control the first and the thirdairflow control members to alternate between being in the first and thesecond states, respectively, wherein the control module is furtheradapted to control the first and the third airflow control members to bein the same states at the same time. Thus the control module couples thefirst and third airflow members to each other, so that the first and thesecond airflows simultaneously will be directed into the first andsecond air passage, respectively, when the first and third airflowcontrol members are in their first, open states. Preferably the controlmodule is also adapted to control the second and fourth airflow controlmembers to be in the same states at the same time, and to be in oppositestates relative to the first and the third airflow control members.Thus, the airflow control module controls the first, second, third andfourth airflow control module so that the first and the second airflowwill simultaneously be either allowed into the respective air passageand be prevented from continuing in the first and second airflowchannels, or to be allowed to continue in the first and second airflowchannels, respectively, while being prevented from entering the airpassages.

According to one embodiment of the invention at least one of the airflowcontrol members comprises a shutter plate mounted on a rotatable shaft,so that the airflow control member is rotatable between its first andits second state. Preferably, all four airflow control members compriseone shutter plate each, mounted on a shaft. Preferably, the shaft isarranged to pass substantially in the middle of the shutter plate and inthe same plane as the shutter plate, wherein the shutter plate isbalanced on the shaft, and the moment of inertia during a rotation islow. In another embodiment the shaft may be arranged along one end ofthe shutter plate, wherein the shutter plate may be rotated through asmaller angle, while retaining its function. According to one embodimentof the invention the first and the fourth airflow control members aremounted on the same shaft, so that the first and fourth airflow controlmembers rotate with each other. Thus it is possible to turn the controlmembers mounted on the same shaft between their first and second states,by rotating only one shaft and with only one drive unit. Preferably, thesecond and the third airflow control members are also jointly mounted ona second shaft. However, for very large ventilation devices the shutterplates may become heavy, wherein it is preferred to mount each shutterplate on an individual shaft.

According to one embodiment of the invention the ventilation devicecomprises a first casing comprising an inner hollow defining the firstairflow channel, and a second casing comprising an inner hollow definingthe second airflow channel, wherein the first and the second casings arejoined for at least a portion of the length of the first and secondairflow channels. In one embodiment the casings are joined by being heldtogether. In another embodiment the casings are joined by beingseparated by a common partition wall. In yet another embodiment thefirst and second casings are integrated into a single, common casing,and the airflow channels are separated by a partition wall arrangedinside the common casing. Thus, the distance between the airflowchannels is small for these portions, so that the ventilation device ismore compact and occupies less space. Preferably, the air passages arearranged in connection with the joined portions, so that the airpassages are short. Thus, the airflows need not travel a long distancethrough the air passages before reaching into the other channel.

According to one embodiment of the invention the first and the secondairflow channels are separated by a partition wall for at least aportion of the length of the channels, wherein the air passage comprisesan opening in the partition wall. Thus the air passage is very short,and the device may be very compactly designed. Preferably, the partitionwall is common for both airflow channels, so that the partition wallforms a wall in both channels. Hence the distance between the airflowchannels is minimized. Preferably the first air passage comprises anopening to the first airflow channel having a width, which is smallerthan or equal to the width of the airflow channel. Preferably, the widthof the opening is smaller than or equal to half of the width of the wallsurface in which the opening is arranged. Preferably the opening isfurthermore positioned to one side of the wall surface, as seen in thelongitudinal direction thereof. Preferably, the second air passage alsocomprises a second opening to the first airflow channel having a width,which is smaller than or equal to the width of the airflow channel.Preferably the second opening is positioned on the other half of thewall surface, wherein both openings may be located side-by-side.Preferably the device further comprises an internal wall arranged toseparate the two openings, so that different airflows may pass throughthe two openings without mixing. Preferably the wall is arranged insideeither or both of the first and the second airflow channels, in order toprevent mixing of the airflows.

According to one embodiment of the invention the ventilation devicecomprises at least one internal wall arranged to prevent at least amajor part of one of the airflows from entering an air passage.Preferably, the internal wall is arranged to at least partly surroundthe opening to the air passage inside one of the air channels. Thus,mixing of the two airflows is at least partly prevented. According toone embodiment of the invention the at least one internal wall isarranged to cooperate with at least one of the airflow control membersfor preventing at least a major part of at least one airflow fromentering an air passage.

Preferably, the internal wall comprises a first wall part arranged toextend across and to cover at least between 30-60% of the internalcross-section area of the airflow channel. The cross-section area ishere intended to be the cross-section area perpendicular to theextension of the channel. The first wall part may be arrangedperpendicular to the extension of the airflow channel. In anotherembodiment the first wall part may be arranged obliquely relative to thelength direction of the airflow channel, wherein the pressure drop maybe decreased. The first wall part hence forces the airflow into theuncovered half of the airflow channel.

Preferably the internal wall defines an opening for letting the airflowout of or into the air passage, which opening is covered by an airflowcontrol member. Hence the airflow may be regulated and controlled bychanging the state of the airflow member. Preferably the internal wallis arranged to surround the opening in cooperation with a wall of thecasing and/or a flow control member to at least 95%. Preferably, thefirst part of the internal wall is shaped as one, wall-to-wall piece,wherein at least a major part, preferably at least 90%, of the airflowis held together into one single airflow stream.

According to one embodiment the internal wall comprises a second wallpart arranged to separate the first and second airflows from each other.Preferably the second wall part is arranged in the longitudinaldirection of the airflow channel, and/or in the direction of the airflowthrough the ventilation device. In case the airflow passages areopenings in the partition wall the second wall part is preferablyarranged at least partly around the opening, and to separate theopenings and the air passages from each other. Preferably the internalwall then forces the airflows into their correct opening.

According to one embodiment of the invention the ventilation device isarranged to alternate between a first state, in which the ventilationdevice directs the first and the second airflows to pass straightthrough the first and the second airflow channels, respectively, and asecond state, in which the ventilation device directs the first and thesecond airflows to enter a first and a second air passage arrangedbetween the first and the second airflow channels, so that the firstairflow flows from the first airflow channel and into the second airflowchannel through the first air passage, and the second airflow flows fromthe second airflow channel and into the first airflow channel throughthe second air passage. Hence it is ensured that the two airflowsalternate between passing through the first and the secondheat-absorbing bodies, respectively, in order to regenerate heat andsave costs. According to one embodiment of the invention the device isadapted in size so as to allow a first airflow of at least 5 000 m3/min,preferably at least 7 000 m3/min, and most preferably at least 10 000m3/min, based on an air pressure of at the most 2 Bar inside the airflowchannel. Preferably the device is further adapted in size so as tosimultaneously allow a second airflow of at least 5 000 m3/min,preferably at least 7 000 m3/min, and most preferably at least 10 000m3/min, based on an air pressure of at the most 2 Bar inside the airflowchannel. Thus the capacity of the device is suitable for very largeairflows and large ventilation systems.

According to another aspect the invention relates to a ventilationarrangement comprising a first ventilation device as described above,and a heat-absorbing module comprising a first and a secondheat-absorbing bodies connected with the first and the second airflowchannels in the first ventilation device with a first end, and a secondventilation device similarly adapted to control the airflow paths of thefirst and the second airflows to alternately flow to or from the firstand the second heat-absorbing bodies and which is connected with thesecond end of the first and second heat-absorbing bodies. Thus oneairflow control device is arranged on either side of the heat-absorbingmodule. The second ventilation device is preferably also designedaccording to the above, but may also have another designed.

Preferably, both the first and the second ventilation devices areadapted to receive or exhaust each airflow via one and the same openingat all times to a surrounding ventilation system. Thus, the airflowswill be received or exhausted to or from the same air duct in theexternal ventilation system, so that the air ducts connected to thedevices may always carry the same airflow and always in the samedirection. Thus the device may be positioned far from either or both ofthe intake or outlet to the indoor air or the outdoor air, withoutincreasing the volumes of air that need to be moved through the airducts when alternating the airflows, before the new air reaches the heatabsorbing bodies. Hence the ventilation arrangement may be positioned inone part of a building while the intake or outlet for the ventilationsystem is positioned in another part. In particular, it is an advantageto install the ventilation arrangement in the cellar of a building whilepositioning the intake or outlet on the roof of the building.

In another embodiment of the present invention, two or three suchventilation devices and/or heat absorbing modules may be arranged withinthe same housing, forming a separate unit. This gives the advantage thatthe entire unit may be removed or replaced for maintenance or repair.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now to be described as a number of non-limitingexamples of the invention with reference to the attached drawings.

FIG. 1a shows a perspective view of a ventilation device in a firststate according to one example of the invention, and having part of itsside-wall and roof cut open to increase visibility.

FIG. 1b shows a view from above depicting the upper airflow channel inthe ventilation device shown in FIG. 1 a.

FIG. 1c shows a view from above depicting the bottom airflow channel inthe ventilation device shown in FIG. 1 b.

FIG. 1d shows a front view of the device in FIG. 1 a.

FIG. 1e shows a perspective view of the ventilation device in a secondstate, with parts of its side-wall and roof cut open to increasevisibility.

FIG. 1f shows a front view of the device in FIG. 1a in the second state.

FIG. 2 shows another example of an airflow control member positionednext to an air passage according to the invention.

FIG. 3 shows one example of a ventilation arrangement according to oneaspect of the invention.

DETAILED DESCRIPTION

In FIGS. 1a to 1f , one example of a ventilation device 1 according tothe invention is shown. The ventilation device 1 is adapted to controlthe flow paths of a first 3 and a second 5 airflow to alternately flowto a first 6 and a second 8 heat-absorbing body in order to achieve aheat transfer between the two airflows. Thus in a first state of thedevice 1, the first airflow 3 passes the first body 6 so that the firstbody acquires the temperature of the first airflow, while the secondairflow 5 passes the second body 8 so that the second body acquires thetemperature of the second airflow. In a following second state of thedevice 1 the first airflow 3 is directed to pass through the second body8, while the second airflow 5 is directed to pass through the first body6. By letting the device alternate between being in the first and thesecond states, so that the airflows alternate between passing throughthe first 6 and the second 8 bodies, a heat transfer is achieved betweenthe two airflows.

The first body 6 is in this example arranged on top of the second body8, but in another example the bodies may of course be arranged in anyother suitable manner and may also be positioned apart from each other.The bodies 6, 8 are adapted to be connected with the device 1, which isindicated by the dashed lines in FIG. 1a and 1e . In this example theheat-absorbing bodies each comprises a plurality of stacked metal plateshaving a plurality of channels formed between the plates.

The device 1 further comprises a first airflow channel 7 adapted forconducting an airflow through the airflow channel. The first airflowchannel 7 comprises a first end 9 adapted to receive or exhaust thefirst airflow 3, and a second end 11 adapted to be communicating withthe first body. Correspondingly, the device 1 comprises a second airflowchannel 13 comprising a first end 15 adapted to receive or exhaust thesecond airflow and a second end 17 adapted to communicate with thesecond body. In this example, the first airflow channel 7 is positionedon top of the second airflow channel 13 in order for the device to beadapted to the positions of the two heat-absorbing bodies.

The ventilation device 1 further comprises at least one first airpassage 19 connecting the first 7 and the second 13 airflow channels andarranged for leading at least a part of the first airflow 3 from thefirst airflow channel 7 and into the second airflow channel 13. Thus thefirst airflow 3 may be directly directed into the second airflow channel13 and further to the second body, without having to connect the airflowchannels to an intermediate switching device for alternating theairflows.

The ventilation device 1 further comprises a first airflow controlmember 21 adapted to admit the first airflow 3 to flow into the secondairflow channel 13 through the first air passage 19 in a first, openstate, as shown in FIGS. 1e to 1f , and to force the first airflow 3 tocontinue in the first airflow channel 7 in a second, closed state, asshown in FIGS. 1a to 1d . Thus the first airflow control member 21prevents at least a major part of the first airflow 3 from flowing intothe second airflow channel 13 through the first air passage 19 in thesecond state. Hence, by changing the state of the first airflow controlmember 21, the first airflow 3 may be controlled to either pass throughthe first body by letting the first airflow continue through the firstairflow channel, or to pass through the second body, by admitting thefirst airflow 3 into the second channel 13.

The ventilation device further comprises a second airflow control member23 adapted to admit the first airflow 3 to flow past the first airpassage 19 and to continue through the first airflow channel 7 in afirst, open state, and to force the first airflow 3 into the air passage19 in a second, closed state, so as to prevent the first airflow 3 fromflowing through the first airflow channel 7. Hence a larger part, andpreferably almost all, of the first airflow 3 will be directed into thesecond airflow channel 13, when the second airflow control member 23 isin its second state. The device 1 also comprises a second air passage 25between the first 7 and the second 13 airflow channels, arranged forleading at least a part of the second airflow 5 from the second airflowchannel 13 and into the first airflow channel 7. The ventilation device1 further comprises a third airflow control member 27 adapted to admitthe second airflow 5 to flow into the first airflow channel 7 throughthe second air passage 25, in a first, open state, and to force thesecond airflow 5 to continue through the second airflow channel 13, in asecond, closed state. Thus the second airflow 5 is prevented fromflowing into the first airflow channel 7 through the second air passage25, in the second, closed state. The device also comprises a fourthairflow control member 29 adapted to admit the second airflow 5 to flowpast the second air passage 25 and to continue through the secondairflow channel 13 in a first, open state, and to force the secondairflow 5 into the second air passage 25 in a second, closed state, soas to prevent the second airflow 5 from flowing through the secondairflow channel 13.

The ventilation device 1 is arranged to alternate between being in afirst or a second state for directing the airflows 3, 5 between thefirst and the second bodies. In the first state of the ventilationdevice 1, as depicted in FIGS. 1a to 1d , the first 21 and the third 27airflow control members are in their second, closed states, while thesecond 23 and fourth 29 airflow control members are in their first, openstates. Hence the first 3 and the second 5 airflows are controlled topass straight through the first airflow channel 7 and the second airflowchannel 13, respectively. In the second state of the ventilation device1, as shown in FIGS. 1e to 1f , the first 21 and third 27 airflowcontrol members are in their first, open states, and the second 23 andfourth 29 airflow control members are in their second, closed states.Hence the first 3 and second 5 airflows are controlled to enter thefirst 19 and the second 25 air passages, respectively, so that the firstairflow 3 flows from the first airflow channel 7 and into the secondairflow channel 13 through the first air passage 19, and the secondairflow 5 flows from the second airflow channel 13 and into the firstairflow channel 7 through the second air passage 25. By providing airpassages 19, 25 between the two airflow channels the airflows may thusbe directed and alternated from within the airflow channels, rather thanleading the airflows to a separate device for alternating the airflows.

The ventilation device further comprises a control module 31 arranged tocontrol the state of the ventilation device 1. In this example thecontrol module 31 is adapted to control the states of at least oneairflow control module 21, 23, 27, 29. The control module 31 maycomprise a microcomputer containing a computer program, or a controlcircuit, for processing signals or other data pertaining to theoperation of the device 1. The control module 31 may further beconnected with a mechanical control system for controlling the movementof the airflow control member or members. In this example the controlmodule 31 comprises drive units in the form of two electrical engines 33for moving the control members, but in another example the controlmodule may comprise drive units in the form of pneumatics. In thisexample the control module 31 is further designed to comprise severalparts, but in another example the control module may be integrated intoa single unit.

The control module 31 is adapted to control the first 21 and the second23 airflow control members to alternate between being in the first andthe second states, respectively. In order to direct at least a majorpart, in this example at least 98%, of the first airflow 3 to therespective airflow channels 7, 13, the control module 31 is adapted tocontrol the first 21 and the second 23 airflow control members to be indifferent states at the same time. Thus the first airflow control member21 will be in its open state so as to admit the first airflow 3 to enterthe first air passage 19, while the second airflow control module 23will be in its second state so as to prevent the airflow 3 fromcontinuing through the first airflow channel 7, and to force the airflow3 into the air passage 19. The control module 31 is similarly adapted tocontrol both the third 27 and the fourth 29 airflow control modules tobe in different states at the same time.

In order to alternate both airflows 3, 5 simultaneously, the controlmodule 31 is further adapted to control the first 21 and the third 27airflow control modules to be in the same states at the same time, andto control the second 23 and the fourth 29 airflow control members to bein the same states at the same time. Thus both the first 3 and thesecond 5 airflows will be controlled to alternate between either passingstraight through the channels or to switch between the channels.

In this example the ventilation device comprises a first casing 35arranged to form a hollow defining the first airflow channel 7. Thefirst casing 35 may for example comprise metal plates bended and weldedinto the desired shape for the casing 35. The ventilation device 1 alsocomprises a similar, second casing 37 adapted to define the secondairflow channel 13 inside the casing 37. The first 35 and second 37casings are in this example joined with each other for at least aportion of the length of the first 7 and second 13 airflow channels. Inthis example the casings 35, 37 are joined for at least a major part ofthe length of the airflow channels. By joining the casings 35, 37together the distance between the airflow channels is short, so that thedevice 1 will be very compact and so that the device will be provided asa single body. In this example the first 35 and the second 37 casingsalso share a common partition wall 39 separating the first 7 and thesecond 13 airflow channels from each other for at least a portion of thelength of the channels, in this example for the major portion of thelength of the channels. Thus the partition wall 39 forms part of thewall for both the first 7 and the second 13 airflow channelsimultaneously.

The air passages 19, 25 are in this example arranged in connection withthe joined portions of the casings 35, 37. Thus the air passages 19, 25are short, since the distance between the two airflow channels 7, 13 isshort. In this example the first 19 air passage comprises a firstopening 41 in the partition wall 39, wherein the first airflow 3 mayeasily pass from the first channel 7 and into the second channel 13through the opening 41. The second air passage 25 similarly comprises anopening 43 in the partition wall for admitting the second airflow 5 intothe first airflow channel 7. In this example, the opening 41 to thefirst air passage 19, has a width, which is smaller than or equal to thewidth of the first airflow channel 7, in this example smaller than orequal to half of the width of the partition wall 39, which is the wallof the first airflow channel 7 in which the opening 41 is arranged. Thefirst opening 41 is further positioned mainly to one side of the surfaceof the partition wall 39, in this example the opening is positionedcompletely within one half of the wall surface in the length directionthereof. Correspondingly, the second opening 43 to the second airpassage 25, also has a width, which is smaller than or equal to thewidth of the first airflow channel 7, in this example smaller than orequal to half of the width of the partition wall 39. The two openings41, 43 are furthermore arranged side-by-side, in level with each otherand positioned on different halves of the partition wall 39. Thus thefirst and the second airflows may pass between the two channels, throughthe openings 41, 43, in level with each other but on different halves ofthe airflow channels.

The ventilation device also comprises a first internal wall 45 arrangedto prevent the second airflow 5 from entering the first air passage 19.The internal wall 45 is also arranged to separate the openings 41, 43 tothe air passages 19, 25 from each other. In this example the firstinternal wall is arranged to at least partly surround the opening 41 inorder to prevent the second airflow 5 from entering the opening 41 andthe first air passage 19. Thus, mixing of the two airflows is avoided.The first internal wall 45 is further arranged to cooperate with thefirst airflow control member 21 for preventing the second airflow fromentering the first air passage 19. In this example the first internalwall 45 is arranged to form an opening to the second channel for lettingthe first airflow out of the air passage 19, which opening is covered bythe first airflow control member 21. Hence the airflow may be regulatedand controlled by changing the state of the airflow control member 21.

In this example both the first airflow control member 21 and theinternal wall 45 are arranged inside the space formed by the secondairflow channel 13. Since the airflow channels are large to allow alarge airflow, there is sufficient space for accommodating the internalwall and the control member. In this example the first wall 45 comprisesone part arranged perpendicular to the flow direction of the airflowsthrough the device, and arranged on the opposite side of the opening 41in the partition wall 39 relative to the airflow control member 21. Theperpendicular part of the wall section is furthermore connected with theside-wall of the casing 35.

The internal wall 45 further comprises a part arranged longitudinallywith the flow direction through the device and in parallel with theside-wall of the casing 35. The longitudinal part is positioned on theopposite side of the opening 41 in the partition wall 39 relative to theside-wall of the casing 35. Hence the internal wall section 45 surroundsthe opening on all sides in conjunction with the side-wall of the casingand with the first airflow control member 21. The internal wall 45, incooperation with the side-wall of the casing 35, further defines part ofthe air passage 19.

The device 1 further comprises a corresponding second internal wall 47arranged inside the space of the first channel 7, and arranged to atleast partly surround the opening 43 in the partition wall 39 forpreventing the first airflow from entering the second air passage 25 inconjunction with the third airflow control member 27.

In this example the airflow control members 21, 23, 27, 29 eachcomprises a shutter plate 49 mounted on a rotatable shaft 51. Thus theairflow control members are rotatable between their respective first andsecond states. In this example the shutter plates are mounted on arotatable shaft passing through the middle of the shutter plate andarranged in the same plane as the extension of the shutter plate. Thusthe moment of inertia when rotating the shutter plates is decreased, sothat the energy consumption for driving the rotation is also decreased.The use of shutter plates arranged on such rotatable shafts gives veryefficient and durable control members for controlling the airflow in thedevice 1. In this example the first 21 and the fourth 29 airflow controlmembers are mounted on the same shaft, so that the first and fourthairflow control members rotate with each other.

Similarly, the second 23 and the third 27 control members are alsomounted on the same shaft. Thus it is possible to control all fourcontrol members with only two drive units 33.

In FIG. 2 a second example of a construction of an airflow controlmember 55 arranged in an airflow channel 56 is shown. The airflowcontrol member 55 comprises a shutter plate mounted on a rotatable shaft59 arranged along one edge of the shutter plate. The airflow controlmember 55 is further positioned in connection with an opening 61 to anair passage, so that the rotatable shaft is arranged along one edge ofthe opening. The shutter plate is further arranged with a length equalto or longer than the height of the airflow channel 56.

In a first state the shutter plate is rotated to cover the opening 61,wherein the airflow is prevented from entering the opening and continuesinside the airflow channel 56. In a second state, as shown in FIG. 2,the shutter plate is rotated so that the opening 61 is left open, and sothat the shutter plate make contact with the ceiling of the airflowchannel 56, wherein the airflow is prevented from continuing inside theairflow channel and is forced into the opening 61 to the air passage.Thus only one shutter plate is necessary for controlling the airflow.

In FIG. 3 one example of a ventilation arrangement 63 according to theinvention is shown. The ventilation arrangement 63 comprises a firstventilation device 65, designed in the same manner as the ventilationdevice 1 described in FIGS. 1a to 1f . The arrangement 63 furthercomprises a heat-absorbing module 67 comprising two heat-absorbingbodies 67A and 67B, wherein the heat absorbing module 67 is arranged influid communication with the ventilation device or airflow controlmodule 65 with a first end of the heating module 67. The ventilationarrangement 63 further comprises a second ventilation device 69 arrangedin fluid communication with a second end of the heat-absorbing module67. Thus each of the two airflows pass through the heat absorbing module67 and both the ventilation devices 65, 69. In this example the firstventilation device 65 is directly connected to the heat-absorbing module67. Similarly, the second ventilation device is directly connected tothe other end of the heat-absorbing module 67, for conduction of theairflows.

The ventilation devices 65, 59 are both adapted to control the airflowpaths of the first and the second airflows to alternately pass betweenthe two heat-absorbing bodies. Hence the paths of the airflows areexchanged on both sides of the heat-absorbing module 67, wherein thedistance between the exchange point and the heat absorbing bodies isshort. This means that the volume of air that has to be moved at eachexchange of the air flows before fresh air reaches the heat-absorbingbodies is small. Thus the efficiency of the ventilation arrangement 63increases. Furthermore, the ventilation arrangement 63 may be positionedfar away from both the intake and outlets of both the indoor air and theoutdoor air.

The ventilation devices 65, 69 and the heat absorbing module 67 are inthis example arranged to be modular and substantially box-like with arectangular shape, whereby the devices and the module are more easilyinstalled. Due to the modular design of the ventilation arrangement 63it is very easy to replace any or all of the devices 65, 69 or themodule 67 by simply disconnecting and removing the desired device ormodule and replacing it with a new device or module in the event offailure.

In FIG. 3 external air ducts 71, 73, 75, 77 are also shown connectedwith the arrangement 63 for conducting an incoming and an outgoingairflow to the device. In this example the first air duct 71 is adaptedto lead the incoming airflow into the device 65 from the outdoors, thesecond air duct 73 is adapted to lead the outgoing airflow outdoors, thethird air duct 75 is adapted to lead the incoming airflow indoors, andthe fourth air duct 77 is adapted to lead the outgoing airflow fromindoors and into the device. The ventilation devices 65, 69 are in thisexample thus arranged to receive or exhaust the same airflow through thesame opening to the ventilation device, wherein the openings to theventilation devices 65, 69 are at all times connected with the sameexternal air duct leading to an intake or outlet.

That is in the arrangement of FIG. 3, in a first stage, the cold,incoming airflow entering the duct or air passageway 71 is directed bythe airflow control module 65 so that it passes through and is heated bythe first body 67B, while cooling the first body 67B and is directed orswitched by the air control module 69 so that it exits the duct 75 asincoming airflow 75A to the interior.

Thus the cold incoming air passes through the first body 67B and acts tocool the first body, that is to transfer cold thermal energy to thefirst body 67B, from the air passing through the first body, so as tostore the cold thermal energy in the first body. Of course this occursonly when a temperature of the cold incoming air is lower than the firstbody,

Also in the first stage and the warm, outgoing airflow 77A passesthrough the duct or air passageway 77 and is directed by the module 69so that it passes through and is cooled by the second body 67A, whileheating the second body. After the second body 67A the air is directedby the module 63 to the duct 73 as an outgoing airstream 73A

Thus the warm outgoing air passes through the second body 67A and actsto heat the second body 67A, that is to transfer heat energy to thesecond body, from the air passing through the second body so as to storethe heat energy in the second body. Of course this occurs only when atemperature of the warm outgoing air is higher than the second body,

Thus in the first stage the cold incoming air passes through the firstbody 67B and not through the second body 67A while the warm outgoing airpasses through the second body 67A and not through the first body 67B.

Subsequently, the airflows are interchanged in a second stage, so thatthe incoming, cold airflow 71A now is directed by the module 63 so thatit passes through and is heated by the second body 67A. Thus the coldincoming air 71A passes through the second body 67A and is heated by thesecond body 67A using the heat energy previously stored in the firststage. Of course this occurs only when a temperature of the coldincoming air is lower than the second body. Also in the second stagewhile the warm second airflow 77A is directed by the modules 69 and 63so that it passes through and heats the first heat-absorbing body 67B.Thus the warm second airflow passes 77A through the first body 67B andis heated by the first body 67B using the cold energy previously storedin the first stage. Of course this occurs only when a temperature of thewarm second airflow is higher than the first body. Thus in the secondstage the warm second airflow air passes through the first body and notthrough the second body while the cold incoming air passes through thesecond body and not through the first body.

Thus, using the first and second stages, a heat-exchange between the twoairflows is achieved. This can be used to transfer heat or hot thermalenergy to the incoming airstream 71A, 75A from the outgoing airstream77A, 73A when the interior is hotter than the exterior or symmetricallyto transfer cool or cold thermal energy to the incoming airstream 71A,75A from the outgoing airstream 77A, 73A when the interior is coolerthan the exterior.

As clearly shown in FIGS. 1a and 3, each of the first and second heatabsorbing bodies 67B and 67B have first and second air passage faces67C, 67D at opposite ends thereof and four closed sides 67E, 67F, 67Gand 67H between said ends;

As clearly shown in FIGS. 1a and 3, the first and second heat absorbingbodies 67A, 67B are each mounted with one of said four closed sides 67Gof the first heat absorbing body 67B lying adjacent to and parallel toone of said four closed sides of the second heat absorbing body 67A andwith the first air passage face 67C of the first heat absorbing bodylying alongside the first air passage face 67C of the second heatabsorbing body and with the second air passage face 67D of the firstheat absorbing body lying alongside the second air passage face 67D ofthe second heat absorbing body;

As clearly shown in FIGS. 1a and 3, the first and second airflowpassageways 75 and 77 are located at a first end of the first aircontrol module 69 and the first face of the first heat absorbing bodyand the first face of the second heat absorbing body 67D are located ata second opposed end of the first air control module 69.

As clearly shown in FIGS. 1a and 3, the third and fourth airflowpassageways 71 and 73 are located at a first end of the second aircontrol module 63 and the second face 67C of the first heat absorbingbody and the second face 67C of the second heat absorbing body arelocated at a second opposed end of the second air control module 63.

As clearly shown in FIGS. 1a and 3, the first and second airflowpassageways 75, 77 are rectangular with four sides with one side of thefirst airflow passageway lying parallel and adjacent to one side of thesecond airflow passageway and the third and fourth airflow passageways71, 73 are rectangular with four sides with one side of the thirdairflow passageway lying parallel and adjacent to one side of the fourthairflow passageway.

As clearly shown in FIGS. 1a and 3, the first and second airflowpassageways 75, 77 face in a common direction at the first end of thefirst air control module 69 and the third and fourth airflow passageways71, 73 face in a common direction away from the first and second airflowpassageways 75, 77 at the first end of the second air control module 63.

As clearly shown in FIGS. 1a and 3, the first and second heat absorbingbodies 67A and 67B are stacked one on top of the other.

As clearly shown in FIGS. 1a and 3, the first air passage faces 67C liein a common plane and the second air passage faces 67D lie in a commonplane.

As clearly shown in FIGS. 1a and 3, the first, second, third and fourthpassageways 75, 77, 71, 73, the first and second air control modules 63,69 and the first and second heat absorbing bodies 67A, 67B are formed asa common assembly for common installation in the building for attachmentto interior and exterior ducts within the building.

The invention is not limited to the examples shown, but may be variedfreely within the framework of the following claims. In particular, thedifferent examples described may be combined or substituted with eachother, and functional part may be interchanged for other parts with acorresponding function.

Furthermore, the functioning of two different airflow control modulesmay be combined into a single control module, as described in relationto FIG. 2. A ventilation arrangement, or device, may comprise three ormore airflow channels and heat-absorbing bodies for conducting three ormore separate airflows. The airflow channels need not be joined but maybe arranged separately, and connected by an air passage in the form ofan air duct or the like.

1. A ventilation apparatus for connection between an exterior and aninterior of a building so that: in a cooling operation, when air in theexterior is hotter than air in the interior, heat is extracted from anexterior air flow passing from the exterior to the interior to cool theexterior air flow passing to the interior; and in a heating operation,when the exterior air is cooler than the interior air, heat is extractedfrom an interior air flow passing to the exterior from the interior toheat the exterior air flow passing to the interior; the apparatuscomprising: a first heat absorbing body and a second heat absorbingbody; a first airflow passageway for connection to the interior of thebuilding so that an airflow can pass therethrough to introduce exteriorair into the building; a second airflow passageway for connection to theinterior of the building so that an airflow can pass therethrough toextract interior air from the building; a third airflow passageway forconnection to the exterior of the building so that an airflow can passtherethrough to pull exterior air into the building; a fourth airflowpassageway for connection to the exterior of the building so that anairflow can pass therethrough to expel interior air out of the building;a first air control module having a first end and a second opposed end;and a second air control module having a first end and a second opposedend; the first heat absorbing body having first and second air passagefaces at opposite ends thereof and four closed sides between said ends;the second heat absorbing body having first and second air passage facesat opposite ends thereof and four closed sides between said ends; thefirst heat absorbing body being arranged so as to: a) transfer hotthermal energy to the first heat absorbing body from air passing throughthe first heat absorbing body when a temperature of the air is higherthan the first heat absorbing body so as to store hot thermal energy inthe first heat absorbing body; and b) transfer cold thermal energy tothe first heat absorbing body from air passing through the first heatabsorbing body when a temperature of the air is lower than the firstheat absorbing body so as to store cold thermal energy in the first heatabsorbing body; the second heat absorbing body being arranged so as to:a) transfer hot thermal energy to the second heat absorbing body fromair passing through the second heat absorbing body when a temperature ofthe air is higher than the second heat absorbing body so as to store hotthermal energy in the second heat absorbing body; and b) transfer coldthermal energy to the second heat absorbing body from air passingthrough the second heat absorbing body when a temperature of the air islower than the second heat absorbing body so as to store cold thermalenergy in the second heat absorbing body; the first and second heatabsorbing bodies each mounted with one of said four closed sides of thefirst heat absorbing body lying adjacent to and parallel to one of saidfour closed sides of the second heat absorbing body and with the firstair passage face of the first heat absorbing body lying alongside thefirst air passage face of the second heat absorbing body and with thesecond air passage face of the first heat absorbing body lying alongsidethe second air passage face of the second heat absorbing body; the firstand second airflow passageways being located at a first end of the firstair control module and the first face of the first heat absorbing bodyand the first face of the second heat absorbing body being located at asecond opposed end of the first air control module; the third and fourthairflow passageways being located at a first end of the second aircontrol module and the second face of the first heat absorbing body andthe second face of the second heat absorbing body being located at asecond opposed end of the second air control module; the first andsecond air control modules being arranged to switch the air flowsbetween the first and second heat absorbing bodies at both ends of theheat-absorbing bodies so that: in a first mode of the cooling operationthe interior air flow is switched by the first air control module topass from the second airflow passageway through the first heat absorbingbody and is switched by the second air control module to pass to thefourth airflow passageway to the exterior to store cold thermal energyin the first heat absorbing body while the exterior air flow does notpass through the first heat absorbing body but instead is passes throughthe third airflow passageway and is switched by the second air controlmodule to pass through the second heat absorbing body and is switched bythe first air control module to pass to the interior through the firstairflow passageway; and in a second mode of the cooling operation theinterior air flow is switched by the first air control module to passfrom the second airflow passageway through the second heat absorbingbody and is switched by the second air control module to pass to thefourth airflow passageway to the exterior to store cold thermal energyin the second heat absorbing body while the exterior air flow does notpass through the second heat absorbing body but instead passes throughthe third airflow passageway and is switched by the second air controlmodule to pass through the first heat absorbing body and is switched bythe first air control module to pass to the interior through the firstairflow passageway while being cooled by the cold thermal energy storedin the first heat absorbing body which has been cooled in the firstmode; in a first mode of the heating operation the interior air flow isswitched by the first air control module to pass from the second airflowpassageway through the first heat absorbing body and is switched by thesecond air control module to pass to the fourth airflow passageway tothe exterior to store hot thermal energy in the first heat absorbingbody while the exterior air flow does not pass through the first heatabsorbing body but instead passes through the third airflow passagewayand is switched by the second air control module to pass through thesecond heat absorbing body and is switched by the first air controlmodule to pass to the interior through the first airflow passageway; andin a second mode of the heating operation the interior air flow isswitched by the first air control module to pass from the second airflowpassageway through the second heat absorbing body and is switched by thesecond air control module to pass to the fourth airflow passageway tothe exterior to store hot thermal energy in the second heat absorbingbody while the exterior air flow does not pass through the second heatabsorbing body but instead passes through the third airflow passagewayand is switched by the second air control module to pass through thefirst heat absorbing body and is switched by the first air controlmodule to pass to the interior through the first airflow passagewaywhile being heated by the hot thermal energy stored in first heatabsorbing body which has been heated in the first mode.
 2. Theventilation apparatus according to claim 1 wherein the first and secondairflow passageways are rectangular with four sides with one side of thefirst airflow passageway lying parallel and adjacent to one side of thesecond airflow passageway and wherein the third and fourth airflowpassageways are rectangular with four sides with one side of the thirdairflow passageway lying parallel and adjacent to one side of the fourthairflow passageway.
 3. The ventilation apparatus according to claim 1wherein the first and second airflow passageways face in a commondirection at the first end of the first air control module, and thethird and fourth airflow passageways face in a common direction awayfrom the first and second airflow passageways at the first end of thesecond air control module.
 4. The ventilation apparatus according toclaim 1 wherein the first and second heat absorbing bodies are stackedone on top of the other.
 5. The ventilation apparatus according to claim1 wherein the first air passage faces lie in a common plane and thesecond air passage faces lie in a common plane.
 6. The ventilationapparatus according to claim 1 wherein the first, second, third andfourth passageways, the first and second air control modules and thefirst and second heat absorbing bodies are formed as a common assemblyfor common installation in the building for attachment to interior andexterior ducts within the building.
 7. A ventilation apparatus forconnection between an exterior and an interior of a building so that: ina cooling operation, when air in the exterior is hotter than air in theinterior, heat is extracted from an exterior air flow passing from theexterior to the interior to cool the exterior air flow passing to theinterior; and in a heating operation, when the exterior air is coolerthan the interior air, heat is extracted from an interior air flowpassing to the exterior from the interior to heat the exterior air flowpassing to the interior; the apparatus comprising: a first heatabsorbing body and a second heat absorbing body; a first airflowpassageway for connection to the interior of the building so that anairflow can pass therethrough to introduce exterior air into thebuilding; a second airflow passageway for connection to the interior ofthe building so that an airflow can pass therethrough to extractinterior air from the building; a third airflow passageway forconnection to the exterior of the building so that an airflow can passtherethrough to pull exterior air into the building; a fourth airflowpassageway for connection to the exterior of the building so that anairflow can pass therethrough to expel interior air out of the building;an air control module having a first end and a second opposed end; thefirst heat absorbing body having a first air passage face at a first endthereof and a second air passage face at a second opposed end thereofand four closed sides between said first and second ends; the secondheat absorbing body having a first air passage face at a first endthereof and a second air passage face at a second opposed end thereofand four closed sides between said first and second ends; the first heatabsorbing body being arranged so as to: a) transfer hot thermal energyto the first heat absorbing body from air passing through the first heatabsorbing body when a temperature of the air is higher than the firstheat absorbing body so as to store hot thermal energy in the first heatabsorbing body; and b) transfer cold thermal energy to the first heatabsorbing body from air passing through the first heat absorbing bodywhen a temperature of the air is lower than the first heat absorbingbody so as to store cold thermal energy in the first heat absorbingbody; the second heat absorbing body being arranged so as to: a)transfer hot thermal energy to the second heat absorbing body from airpassing through the second heat absorbing body when a temperature of theair is higher than the second heat absorbing body so as to store hotthermal energy in the second heat absorbing body; and b) transfer coldthermal energy to the second heat absorbing body from air passingthrough the second heat absorbing body when a temperature of the air islower than the second heat absorbing body so as to store cold thermalenergy in the second heat absorbing body; the first and second heatabsorbing bodies each mounted with one of said four closed sides of thefirst heat absorbing body lying adjacent to and parallel to one of saidfour closed sides of the second heat absorbing body and with the firstair passage face of the first heat absorbing body lying alongside thefirst air passage face of the second heat absorbing body and with thesecond air passage face of the first heat absorbing body lying alongsidethe second air passage face of the second heat absorbing body; the aircontrol module being arranged to alternate the air flows between thefirst and second heat absorbing bodies so that: in a first mode of thecooling operation the interior air flow passes through the first heatabsorbing body to the exterior to store cold thermal energy in the firstheat absorbing body while the exterior air flow does not pass throughthe first heat absorbing body but instead passes through the second heatabsorbing body to the interior; and in a second mode of the coolingoperation the interior air flow passes through the second heat absorbingbody to the exterior to store cold thermal energy in the second heatabsorbing body while the exterior air flow does not pass through thesecond heat absorbing body but instead passes through second heatabsorbing body the first heat absorbing body to the interior while beingcooled by the cold thermal energy stored in the first heat absorbingbody which has been cooled in the first mode; in a first mode of theheating operation the interior air flow passes through the first heatabsorbing body to the exterior to store hot thermal energy in the firstheat absorbing body while the exterior air flow does not pass throughthe first heat absorbing body but instead passes through the second heatabsorbing body to the interior; and in a second mode of the heatingoperation the interior air flow passes through the second heat absorbingbody to the exterior to store hot thermal energy in the second heatabsorbing body while the exterior air flow does not pass through thesecond heat absorbing body but instead passes through the first heatabsorbing body to the interior while being heated by the heat stored infirst heat absorbing body which has been heated in the first mode; theair control module having a first end and a second end with the firstend arranged at said first end of the first and second heat absorbingbodies; wherein the first and second airflow passageways are rectangularwith four sides with one of the four sides of the first airflowpassageway lying parallel and adjacent to one side of the four sides ofthe second airflow passageway; wherein the third and fourth airflowpassageways are rectangular with four sides with one of the four sidesof the third airflow passageway lying parallel and adjacent to one sideof the four sides of the fourth airflow passageway; wherein the firstand second air passageways are located at one of the second end of theair control module and the second end of the heat absorbing bodies;wherein the third and fourth airflow passageways are located at theother of the second end of the air control module and the second end ofthe heat absorbing bodies; and wherein the first and second airpassageways face in a direction opposite to the third and fourth airpassageways.
 8. The ventilation apparatus according to claim 7 whereinthe first and second heat absorbing bodies are stacked one on top of theother.
 9. The ventilation apparatus according to claim 7 wherein thefirst air passage faces lie in a common plane and the second air passagefaces lie in a common plane.
 10. The ventilation apparatus according toclaim 7 wherein the first, second, third and fourth passageways, thefirst and second air control modules and the first and second heatabsorbing bodies are formed as a common assembly for common installationin the building for attachment to interior and exterior ducts within thebuilding.